Pestes, U.S. Pat. No. 6,645,127, discloses a wheelchair exercise apparatus in which a wheelchair is driven up a ramp onto a platform. A pair of side by side rollers, which extend above the platform, support the wheelchair driving wheels. A clamp mechanism holds the wheelchair immovably on the rollers. The rollers are connected to a flywheel which provides the momentum associated with actual wheelchair operation. One difficulty with this prior art apparatus is that elderly people or people who are new to using a wheelchair may have limited arm strength and overcoming the resistance caused by driving two rollers for an extended period of time may not be possible for them. However, it is very difficult to drive the driving wheels of a wheelchair up onto a single roller and lock it in place with the driving wheels centered on the roller.